Process of roasting and sintering ore.



A. S. DWIGHT.

PROCESS OF ROASTING AND SINTERING ORE.

RENEWED FEB. 23

APPLICATION FILED MAY 28, 1907.

Patented Mar. 23 1909.

c on c ARTHUR s. nwien 'r, or IoLIET,

ILLINOIS,- ASSIGNOR ro FRED BENNITT, TRUSTEE OFJOLIET, I'LLINOIs.

PROCESS OF ROASTING AND SINTERING ORE.

Specification of Letters Patent.

Patented March 23, 1909.

Application Kay 28, 1907, Serial no. 876,188. Benewedlebruary 23, .1909. Serial No. 479,497.

T0011 whom it may concern:

Be it known that I, ARTHUR S. DWIGHT, a citizen of the United States, residing at Joliet, in the county of Will and State of Illineis, have invented certain new and useful Improvements in Processes of Roasting and 'Sintering Ore,. of which the following is a s ecification, reference being had therein to 11 pt e accompanying drawing. This invention relates to improvements in the processes for treating metal bearing ma terials, articularly ores of themetalsulfid' class, t ese improvements relating to proc eases-such as arep'resented in the applications Serial Numbers 307431 and {32 83877, filed by myself 'ointly with Richard" L. Lloyd on the 22n da of March, 1906,'and on the th day -of'alu y, 1906, respectively.

described a number of devices for suppo'rtin ,and'trans'porting masses of ore to be treated and for carrying on the treatment in such way that the desulfurizing and sintering of theore'could be done more thorou y and completelythan had been attaine by any %pxparatus?lor, process theretofore known. ereinwere described the generic features aswell: as some. specific matters incident to the --invention. 30 1,;have. devised certain improvements which I have found to be applicable under many circumstances in the treatment of ores of the classreierred to, and they are hereinp esen d- In order that the present improvements may be full understood I present herewith drawings. w 'ch will illustrate some of. the numerous iormsof devices that can be emplciyed in carryingout the recess. 7 1

0/. v igure 1 1s a longitudina section of 'me'ch- Amen which can be used to hold ore and it While it is being subjected to the which 1 characterizes my present improvement. -Fig. 2- is a cross section on the line-2 2 of the apparatus shown in Fig.

1. 3 is a cross section on the line .33 offEig 1. Fig. 4' is a longitudinal .section' showing seine pf the same parts that are resentedinFig. 1, but ona larger scale. 60 g 5, .6 and Tare sectional views res ectiyely illustratinglmodificetionsin the met 7 od treatingthe -ore. Figs. 8,9 1.0,, are detail views showing different forms of carrier mechanism.

In the said applications were illustrated and It will be understood that the illustrations and the drawings are more or less diagrammatic and conventional in character.

Fig. 1 illustrates a mechanism in which use .is made of an endless horizontal carrier; and Fig.4 is asectional viewof someof the parts in Fig. 1 on a larger scale. The carrier is indicated as a' whole by 5. It may-be made in any. suitable Way, for example it may be con j'structed of flat bars 5 hinged as shown in Fig. 8; or it may be similar to What are'known as pan conveyers, as in Fig. 10, that is, conveyers formed in sections 5* which are secured to 'a chain or chains 5*; or it may be built up of link bars, 5 as shown in Fig. 9.

" But as above remarked the conventional illustration in Figs. 1, 2, 3' and-4 is suflicient to convey an understand of how the inventioncan be carried out. I he conveyer 5 is mounted u on wheels, pulleys, or drums, as at 2,2; he-ore supporting art'er floor of the convey'er' is provided wit perforations, orpassages for the free movement of air or gas. At 1 a hopper is provided, it'be'in'g adapted to contain thefines or fine ore inaterialswhich constitute the princi a'l part of the mass thati's to be treated. escapes through the-mouth ,at 26 directly above the conveyer; and is deposited upon the latter in a layer orstream 23 of suitable depth and width. The verticai sides of the mass may be sustained or confined in any preferred way, as for instance by walls 27. At

present for pur oses of description and illustrationit may e assumed that the materials to which reference is made are typified by galena or the sulfide of copper or iron, se "arate or mixed. It is desired to submit t'is material to such treatment that it will not only be completely desulfurized but also sintered throughout, that is to say that after the desulfurizing there will be reduced a coherent sintered mass in suita'b e condition.

for immediate use in the blastfurnace. For I the desulfurizing of the ore in the layer or stratum 23 :on the c onveyer the sum-eels ments are ignited, and the combustion thus started is'conti'nued until the sulfur bodies are entirely oxidized. The i iting. can be effecter'i at 10' where is situate a'horizontally arranged gas pipe with jet orifices, this pi e being arranged on'lines transversely to the conveyor and immediatelybelow the upper run thereof at points near the hopper mouth 26, the orifices being arran ed so that the flame jets 19 impinge upon t e lower surface of the stratum of ore as it advances from the hopper. The combustion thus started is maintained, as the stream or layer 23 advances with the conveyer, by means of an air supply furnished from the box at 6. This is shown as being situated between the upper and lower ,runs of the conveyer 5. Air is supplied to this distributing box through the trunk or. duct 7 which communicates with a fan or pressure device 20. The box 6 may have a hinge section 6 to permit cleaning. As the layer or streamof ore advances over the air supply mechanism the combustion in the ore mass is supported and it gradually rises as shown at 22 until the upper surface of the layer is reached, the. sinter being shown at 24. As is fully set forth in earlier ap lication filed by myself solely and said app ications filed by myself jointly with R. L. Lloyd, it

has been discovered that it is practically impossible to efiect the complete sintering of a mass of ore of this character at the time of or immediately after the desulfurizing thereof, if the currents of air which support the combustion are passed through the mass in such way as to travel toward and escape at an unrestrained surface. And in the said applications I have madev provisions for e 'ecting the holding ofthe ore particles in quiescence at the place where the air or the gases of combustion or reaction escape. One of the objects of the present inventlon is to provide anefiectual restraining o'fthe ore without requiring the supplemental metallic or mechanical parts heretofore provided by me, accom llShlIlg it in such way that the means use forthis urpose can remain in the sinter or 1 be wit drawn therewith and subsequently introduced into the smelting furnace if required. I have found that the particles of the fine ore in the'stratum at or near the upper surface, where air and gases escape, can e satisfactorily held in place until they are effectually sintered, by means of a layer of large particles or lumps of ore of the same consistency or chemical constitution as the finesthemselves. And the manner of using these lumps or blocks as a restrainin means for the fines is illustrated in the said igs. 1 to 4.

12 indicates a hop er supplemental to that at 1, and preferably ocated directly adjacent thereto. In this ho er there is placed a store of the lumps or b ocks of larger sizes of the ore, and itis so placed that a thin layer 21 of these passes from its lower end and is deposited evenly and smoothly upon the to of the layer or stream of fines or more or fess pulverulent mass that is delivered from the oppler 1. At 13 I arrange a screen above e 0 per 1 upon which the material can be centra y prlaced which screen acts to se arate the fines om the coarser particles, t e forcase the air is drawn downward from the 1 or particles of the sulfid ore rest upon and are distributed over the top surface of the stream or layer 23 of fines. As is now well known, the air which is forced upward through an ore mass of this sort tends to lift and agitate the particles of the fines near the up er surface of the mass, and this agitation, disturbance and displacement prevents the sintering of a large percentage of the material. And it has also been found that if this disturbing action can be revented, a complete sintering of the entire ody from the bottom to the to can be attained. When the restraining or old- 85 ing means are such. as here described, the

less extent unites with the lumps or blocks 21 of larger size which have been placed on top of the stream and the mass is ready for introduction to the smelting furnace. The union, however, of the upper stratum with the sinter of the lower stream is not essential, as it is common practice to introduce to the smelting furnace not only fines from the roasting'furnace, but more or less of the raw sulfid ore in lumps or blocks, this depending upon the metallurgical conditions, the chemical constituents and the like. And not only is it true that such a complonent of the charge for the blast furnace as as just been described can be used as a retaining device for roperly holding the fines while being desu rized and sintered, but I have also foundthat other comparatively coarse ingredients of the furnace charge can be likewiseused.

InFig. 5 I have shown an apparatus which is adapted to deliver a stratum of crushed lime-rock to the lower surface of the layer or stream of fines, the quantity being of such proportion that it can be introduced with the desulfurized mass in the smelting furnace. Here there is a hop er 26 for the fines and a hopper 29 for the ime rock or similar material. Use is made of a conveyer 30 substantially similar to that above described, mounted on the wheels or drums at 31, 32-. The layer 33 of lime rock or similar material is interposed between the conveyer and the sulfid ore and serves to distribute the air to the bottom surface of the layer or stream 34. The upper surface of the layer is not provided with a retaining device because in this top through the bottom into the box. 35, from which it is exhausted by any suit-, able apparatus such as the fan at 38. The ore is ignited by the gas jets supplied from the pipe at 37 situated above the upper sur- 130 si ear face of the ore. In this case the combustioncan be combined with those performed by.

devices such as shown in Fig. 1. 29* is a hopper for supplying a layer 42 of lime rock or equivalent material to the conveyor 39. 40 is a receptacle for supplying a layer or stream 43 o the sulfid fines, and from the hopper or rece tacleat 41 a stratum or layer 44 of blocks or umps of sulfid ore is delivered and deposited upon the top of the fine ore. Igniting flames 45 are supplied from the gas pipe at 45, the 'gas jets here impinging upon the combustible ore at the lowerpart of the stream 43 just as it leaves the ho per 40 and immediately before coming to t e paths of the forced air currents; In this case the air is forced u ward under pressure, it being delivered t rough the ipe 48 to the box {17 from which it passes to the ore mass and upward through the latter. It will be understood thatso far as concerns the sulfurizing and the sintering and the holding in place orkeeping in quiescence the particles at the upper part of the mass it is not necessary to have anore holder which moves or advances during the operation. I

'In Fig. 7 I have shown an apparatus for treatin' stationary masses of ore in the wa referre I to. The stationary holder is lildl-r cated by 14, it being provided with an ore I support which has numerous air passages and below which there is an air receiving and distributing chamber 16. Air is sup- ].ied under pressure to this chamber, and it Is forced upward therefrom throu h the ore mass at 17. Upon the top of t e fines I lace a stratum of the coarser particles or umps of ore or a layer of lime rock or the like, as shown at 18, this as above'described preferably being part of the charge which is subsequent introduced into the smelting furnace, ere as in the mechanism above described the result attained is that the coarser articles at the top sup 1y a weight 5 for hol 'ng down in position tl ie finer particles in the upper stratum of the mass, and

they are heldin' such way that at the time of the generation of the heat, say by' oxidation and desulfurization, the are in proper confdition and in proper re ative positions for quickly and readily sintering together to form large cakes or blocks ready for introduction into the furnace.

' .WhatI claim is:

1.The process for treating metal bearing materials containing combustible elements,

which consists in arranging a mass of the material in fine condition between two oppositely arranged holders or retainers one of 65, which consists of particles of rock or ore relatively larger than the particles of fines, igniting. the combustible elements of the mass, and allowing combustion supportin gas to pass through the mass of: fines.- an throughthe two opposite retaining means,

1 substantially as set forth. r

2. The process for treating metal bearing materials containing combustible ingredients, which consists in arranging a mass ofthe material in fine condition upon a holding device, i niting the ore at the surface of the mass ad acent to the said holding device, causing combustion supporting gas to enter the mass at the surface of ignition, applying to the opposite surface of the mass a series or stratum of particles oft-ore or rock relatively larger than the particles'of fines, whereby the stratum of'fines alon the said opposite surface are restrained or lield against agita tion and disturbance during combustion and a5 sintering, substantially as set forth.

3. The process for treating metal bearing materials containing combustible elements, which consists in arranging a mass of the material while in relatively fine condition upon a holder or retainer, placing in contact with the mass an opposing retainer composed of a series or stratum of particles separable from each other and relatively larger than the particles of the fines, igniting the combustible elements ot the mass at points near one of the-said retainers, causing combustion supportin gas to pass through the mass from the si e thereo adjacent to the place of ignition and toward and through,

the opposite retainer, and maintaining the particles of the fines in quiescence during the combustion and sintering, substantially as set forth.

4. The process for treating-metal bearing materials containing combustible elements which consists in arranging a mass of the material in fine condition. between two, oppositely arranged holders or retainers, one of which consists of. particles of rock or ore relatively larger than the particles of fines, igniting the combustible elements of the mass, allowin combustion "supporting gas to pass throug the mass offines and through the two opposite hol'dersoli retainers, sintering the massof fines and causing the relativel' larger particles ct one of said retainers. to a here to or ag lomerate with the sintered fines, substantia y as set forth.

5. The process for treating metal bearing materials containing combustible elements,

which consists in arranging amass ofthe tially as set forth to restrain the particles of the fines from agitation or disturbance, substantially as set forth.

'7. The process for treating metal bearing materials containing combustible elements which consists in arranging a mass of the materials in fine condition between two oppositely arranged holders or retainers, one of which consists of particles of rock or ore relatively larger than the particles of fines, moving the said retainers in one direction continuously, across a region of combustion, causing currents of combustion supporting gas to move transversely to the path of the retainers across the region of combustion, igniting the combustible elements of the mass, and sintering the mass of fine material, substantially as set forth.

8." The process for treating metal bearing materials containing combustible elements, which consists in arranging a mass'of the ma terial while in fine condition substantially as set forth whereby a current or currents of combustion su porting gas are permitted to pass through t e mass, holding the said mass between two retainers adapted to restrain the particles of the fines against agitation and disturbance, one of the said retainers being formed of particles of material adapted to be introduced into the blast furnace, igniting the combustible elements in the mass, causing internal combustion in said mass between;

the said retainers, and supporting the com: bustion by the said current or currents of gas, "substantially as set forth.

9. The process for treatlng sulfid ores containing'combustible elements which consists in arranging a mass of the ores while in fine condition substantially as set forth whereby a current or currents of combustion supporting gas are permitted to pass through the mass, holdingthe said mass between two retainers adapted to restrain the particles of the fines against agitation and disturbance, forming one of the said retainers of articles of sulfid ore relatively larger than t Y e particles of the fines, igniting the sulfur ,elements in the mass, causing internal combustion in said mass between the said retainers and sup porting the combustion by the said current or currents of gas.

10. The process for roasting sulfid ores containing combustible elements, which consists in arranging a mass of the ore while in fine condition substantially as set forth whereby a current or currents of combustion supporting gas are ermitted to ass through the mass, holding t e said mass etween two retainers adapted to restrain the particles of the fines against agitation and disturbance, one of the said retainers being formed of par: ticles of material adapted to be introduced into the blast furnace, igniting the combustible elements in the mass of fines, and causing internal combustion thereof between the said retainers.

11. The process for roasting sulfid ores containing combustible elements which consists in arranging a mass of the ore while in fine condition substantially as set forth whereby a current or currents of combustion supporting gas are permitted to ass through the mass, holdin the said'mass etween two retainers adapte to restrain the particles of the fines against agitation and disturbance, forming one of the said retainers of particles of material relatively lar er than the articles of fines and adapte to be intro uced into the blast furnace, igniting the sulfur elements in the mass, causing internal combustion in said mass between the saidretainers and supporting the combustion by the said current or currents of gas.

12. The process for roasting and sintering 'sulfid ores containing combustible elements, which consists in arranging a mass of the ore while in fine condition in contact with a holder or retainer, igniting the combustible elements of the ore at points near the said retainer, causing a combustion supporting gas to pass through the ore fines, placing in contact with the mass a stratum or series of articles of the sulfid ore relatively larger t an the particles of the fines and arranging them substantially asset forth to restrain the particles of fines from agitation and disturbance during the roasting and sintering, substantially as set forth.

13. The process for treating metal bearing materials preparatory to introducing them into' a blast furnace, which consists in forming a stratum or stream'of one of the ingredients of the blast furnace charge, ap lying to .the said stratum or stream a supp emental stratum or stream of a second ingredient for the blast furnace charge, permitting, a current or currents of air or gas to pass through the said strata or streams, raising the' heat materials preparatory to introducing them into a blast furnace, which consists in forming a stratum or stream of one of the ingredients of the blast furnace charge containing combustible ingredients, applying to the said stratum or stream a supplemental stratum or stream of a second ingredient for the blast furnace charge, permitting a current or currents of combustion supporting gas to pass through the said strata or streams, igniting the said combustible elements, causing internal combustion in one of the said strata or streams, raising the heat by internaLcombustion in the interior to the sintering temperature and causing the particles of both of the said strata or streams to agglomerate by the said sinterin and finally forming from the agglomerate materials blocks or cakes for introduction into the blast furnace, substantially as set forth.

15. The process for treating metal bearing materials preparatory to introducing them into a blast furnace, Which consists in forming an advancing stream or stratum of one of the ingredients of the blast furnace charge containing the combustible ingredients, a plying to the said stratum or stream Whl e it is advancing a supplemental stream or stratum of a second ingredient of the blast furnace charge, moving the said strata or streams across a region of combustion, causing currents of combustion supporting gas to pass through the said strata or streams transversely to their paths of advance, igniting the combustible elements, and raising the heat by internal combustion to the sintering temperature and causing the particles of the stratum or stream containin the combustible elements to be sintere and agglomerated, substantially as set forth.

In testimony whereof I aflix my signature, in presence of two Witnesses.

ARTHUR S. DWIGHT.

\Vitnesses:

G. E. SEYMOUR, SoL SEKULSKY. 

